This article highlights the work of audio forensics experts and provides an introduction to the field of forensic acoustics; it discusses several key elements, terms, and historical origins of the field in the U.S. judicial system, as well as challenges of determining digital files’ authenticity.
The author of this article provides basic information about what forensic acoustics is and the scope of what falls under its purview. He addresses concerns from a 2009 U.S. National Research Council report that criticized many forensic fields, including audio forensics, for lacking scientific evaluation of reliability and error rates, and the resulting decision that forensic investigations should be based on unquestionably objective interpretation and not subjective opinions. The article begins with an introduction to what forensic acoustics is, and what forensic acoustics experts do, noting that those experts who deal with recorded evidence are typically consulted about three concerns: authenticity, enhancement, and interpretation. The article goes on to discuss the history of forensic acoustics in the U.S. court system, with special attention paid to critical court cases, such as United States v. McKeever (1958) and the Watergate scandal of 1971. Finally, the article discusses modern audio forensics and innovations including: audio scene “fingerprinting;” proliferation of personal audio/video recording devices; transportation accident investigations, such as cockpit voice recorders (CVRs), also known as “black boxes;” and the need to assess the fidelity of audio forensic findings.